Max Friends Attend Concert

Given a group of friends and a set of available ticket prices, determine the maximum number of friends who can attend the concert. Each friend can purchase at most one ticket, and a friend can only buy a ticket if the amount of money they have is greater than or equal to the ticket price.

Formally, you are given two lists: one representing the money each friend has, and another representing the available ticket prices. Let \( arr \) be a list of \( n \) integers and \( prices \) be a list of \( m \) integers. We need to find the maximum number of pairs such that for each pair, \( arr[i] \geq prices[j] \). A greedy approach where both lists are sorted and then matched using a two-pointer technique will yield the solution.

inputFormat

The input is read from stdin and has the following format:

n m
arr[0] arr[1] ... arr[n-1]
prices[0] prices[1] ... prices[m-1]

• \( n \) is the number of friends.
• \( m \) is the number of available ticket prices.
• arr is a list of \( n \) integers representing the amount of money each friend has.
• prices is a list of \( m \) integers representing the ticket prices.

outputFormat

Output a single integer to stdout representing the maximum number of friends that can attend the concert.

## sample

5 3
20 15 30 10 50
10 25 50

3

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